forked from Minki/linux
ccd26741f5
Perf record with verbose=2 already prints this information along with
whole lot of other traces which requires lot of scrolling. Introduce
an option to print only perf_event_open() arguments and return value.
Sample o/p:
$ perf --debug perf-event-open=1 record -- ls > /dev/null
------------------------------------------------------------
perf_event_attr:
size 112
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|PERIOD
read_format ID
disabled 1
inherit 1
exclude_kernel 1
mmap 1
comm 1
freq 1
enable_on_exec 1
task 1
precise_ip 3
sample_id_all 1
exclude_guest 1
mmap2 1
comm_exec 1
ksymbol 1
bpf_event 1
------------------------------------------------------------
sys_perf_event_open: pid 4308 cpu 0 group_fd -1 flags 0x8 = 4
sys_perf_event_open: pid 4308 cpu 1 group_fd -1 flags 0x8 = 5
sys_perf_event_open: pid 4308 cpu 2 group_fd -1 flags 0x8 = 6
sys_perf_event_open: pid 4308 cpu 3 group_fd -1 flags 0x8 = 8
sys_perf_event_open: pid 4308 cpu 4 group_fd -1 flags 0x8 = 9
sys_perf_event_open: pid 4308 cpu 5 group_fd -1 flags 0x8 = 10
sys_perf_event_open: pid 4308 cpu 6 group_fd -1 flags 0x8 = 11
sys_perf_event_open: pid 4308 cpu 7 group_fd -1 flags 0x8 = 12
------------------------------------------------------------
perf_event_attr:
type 1
size 112
config 0x9
watermark 1
sample_id_all 1
bpf_event 1
{ wakeup_events, wakeup_watermark } 1
------------------------------------------------------------
sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8
sys_perf_event_open failed, error -13
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.002 MB perf.data (9 samples) ]
Committer notes:
Just like the 'verbose' variable this new 'debug_peo_args' needs to be
added to util/python.c, since we don't link the debug.o file in the
python binding, which ended up making 'perf test python' fail with:
# perf test -v python
18: 'import perf' in python :
--- start ---
test child forked, pid 19237
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: /tmp/build/perf/python/perf.so: undefined symbol: debug_peo_args
test child finished with -1
---- end ----
'import perf' in python: FAILED!
#
After adding that new variable to util/python.c:
# perf test -v python
18: 'import perf' in python :
--- start ---
test child forked, pid 22364
test child finished with 0
---- end ----
'import perf' in python: Ok
#
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191108094128.28769-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
54 lines
1.3 KiB
Plaintext
54 lines
1.3 KiB
Plaintext
perf(1)
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=======
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NAME
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----
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perf - Performance analysis tools for Linux
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SYNOPSIS
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--------
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[verse]
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'perf' [--version] [--help] [OPTIONS] COMMAND [ARGS]
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OPTIONS
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-------
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--debug::
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Setup debug variable (see list below) in value
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range (0, 10). Use like:
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--debug verbose # sets verbose = 1
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--debug verbose=2 # sets verbose = 2
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List of debug variables allowed to set:
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verbose - general debug messages
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ordered-events - ordered events object debug messages
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data-convert - data convert command debug messages
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stderr - write debug output (option -v) to stderr
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in browser mode
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perf-event-open - Print perf_event_open() arguments and
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return value
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--buildid-dir::
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Setup buildid cache directory. It has higher priority than
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buildid.dir config file option.
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-v::
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--version::
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Display perf version.
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-h::
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--help::
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Run perf help command.
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DESCRIPTION
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-----------
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Performance counters for Linux are a new kernel-based subsystem
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that provide a framework for all things performance analysis. It
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covers hardware level (CPU/PMU, Performance Monitoring Unit) features
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and software features (software counters, tracepoints) as well.
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SEE ALSO
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--------
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linkperf:perf-stat[1], linkperf:perf-top[1],
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linkperf:perf-record[1], linkperf:perf-report[1],
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linkperf:perf-list[1]
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